In the case of a conventional electromagnetic radiation emitting assembly, called assembly hereinafter, white light can be generated by means of additive color mixing. For this purpose, by way of example a material comprising phosphor can be applied to an electromagnetic radiation emitting component, called component hereinafter, for example, an LED. The material comprising phosphor, which can also be referred to as converting material or conversion material, converts the electromagnetic radiation generated by the component with regard to its wavelength. By way of example, blue light can be generated by means of the component and can be converted into yellow light by means of the conversion material. The mixture of converted, for example, yellow, and non-converted, for example, blue, light then appears white.
The assemblies are firstly produced in a component assemblage comprising a plurality of the components. The component assemblage can be a wafer, for example. The properties of the individual components, for example, of the LEDs, in a wafer differ from one another. The properties are, for example, physical properties, for example, forward voltages, wavelengths of the generated light and/or brightnesses of the generated light. In this regard, one component of a wafer can generate light having a different brightness than another component of the same wafer under otherwise identical boundary conditions. The properties of a component are thus individual and are therefore also referred to hereinafter as component-individual properties.
After the singulation of the components from the component assemblage, the material comprising phosphor, for example, in the form of phosphor layers, for example, in the form of phosphor laminae, can be applied to the components. One of the assemblies is formed by at least one component with at least one phosphor layer. However, the phosphor layers cannot be applied to all the components exactly identically. As a result, the amount of phosphor required for the white conversion can vary from component to component.
If the properties of the components deviate from one another, in the case of the corresponding assemblies this can result in different color loci for the generated light, even if the amounts of phosphor and/or, for example, the thicknesses of the phosphor layers are identical in the case of the corresponding assemblies. If the amounts of phosphor deviate even only slightly from one another, in the case of the corresponding assemblies this can likewise result in different color loci for the generated light, even if the properties of the components are identical.
It is known, in order nevertheless to obtain assemblies with which identical or at least very similar color loci are achievable, to sort the components according to their component-individual properties, for example, into so-called bins. The conversion material is applied by means of screen printing or molding methods, for example, in which conversion laminae are produced for the respective component geometries and are likewise sorted into bins in accordance with their properties. By way of example, the degree of conversion of the phosphor laminae is measured as a property. This is followed by determining which phosphor laminae match which components in order that as many of the assemblies as possible generate light having the desired color and/or the desired color locus. After, the matching phosphor lamina is adhesively bonded onto the correct component.
Furthermore, it is known to produce only a partial covering of the phosphor layer on a phosphor region of a component, but these partial coverings are always identical geometrically and are not adapted to the properties of the component.